The Role of Grain Boundary Sites for the Oxidation of Copper Catalysts during the CO Oxidation Reaction
Journal article, 2023

The oxidation of transition metal surfaces is a process that takes place readily at ambient conditions and that, depending on the specific catalytic reaction at hand, can either boost or hamper activity and selectivity. Cu catalysts are no exception in this respect since they exhibit different oxidation states for which contradicting activities have been reported, as, for example, in the catalytic oxidation of CO. Here, we investigate the impact of low-coordination sites on nanofabricated Cu nanoparticles with engineered grain boundaries on the oxidation of the Cu surface under CO oxidation reaction conditions. Combining multiplexed in situ single particle plasmonic nanoimaging, ex situ transmission electron microscopy imaging, and density functional theory calculations reveals a distinct dependence of particle oxidation rate on grain boundary density. Additionally, we found that the oxide predominantly nucleates at grain boundary-surface intersections, which leads to nonuniform oxide growth that suppresses Kirkendall-void formation. The oxide nucleation rate on Cu metal catalysts was revealed to be an interplay of surface coordination and CO oxidation behavior, with low coordination favoring Cu oxidation and high coordination favoring CO oxidation. These findings explain the observed single particle-specific onset of Cu oxidation as being the consequence of the individual particle grain structure and provide an explanation for widely distributed activity states of particles in catalyst bed ensembles.

CO oxidation

plasmonic nanoimaging

DFT

single particle

copper nanoparticles

grain boundary sites

surfaceoxidation

Author

Sara Nilsson

Chalmers, Physics, Chemical Physics

John N. El Berch

University of Pittsburgh

David Albinsson

Chalmers, Physics, Chemical Physics

Joachim Fritzsche

Chalmers, Physics, Chemical Physics

Giannis Mpourmpakis

University of Pittsburgh

Christoph Langhammer

Chalmers, Physics, Chemical Physics

ACS Nano

1936-0851 (ISSN) 1936-086X (eISSN)

Vol. 17 20 20284-20298

Subject Categories

Inorganic Chemistry

Materials Chemistry

Condensed Matter Physics

DOI

10.1021/acsnano.3c06282

PubMed

37796938

More information

Latest update

10/30/2023